og12 117 今天被他们弄晕了

zhangzaza

关于星系的这篇文章，完全晕，求翻译： it has been known for some time that outside the bright nucleus of a typical spiral galaxy luminosity falls off rapidly with distance from the center .  还有文中的mass是什么意思，具体一点，特别是117题weaken，从何下手？能稍微给我解释下不

zhangzaza

谢谢撒！终于懂了

hutengqi

It has been known (for some time) that(outside the bright nucleus of a typical spiral galaxy)luminosity falls off rapidly with distance from the center.

这个事实已经被人们所知（有一段时间）了，那就是（在典型旋转星系明亮内核之外），亮度随着距离中心的距离（增加）而急剧下降。